Answer:
A. The gene for making hair WILL NOT BE expressed in the lining of the stomach.
Explanation:
Gene expression is the process by which the instructions in our DNA are converted into a functional product, such as a protein.
Answer: A. The alleles that a person has.
Answer:
The cells in the retina (called rods and cones) that convert light energy into nerve energy are called photo-receptor cells.
Explanation:
Answer: True
Succession is the phenomena in which changes in the biotic and abiotic factors of the environment leads to change in the ecosystem. A succession is a process in which a biological community is replaced by another biological community until a mature ecosystem is formed this process is influence by environmental factors. Primary succession is the primitive environment where no biotic community previously existed it is followed by secondary and subsequent succession were life forms develop and form an ecosystem. Some of the environmental factors are:
Topographical : These are the change in the region or habitat were succession occurs. Landslides, volcanic eruption, glacier melting etc. are the examples , as these topographical changes can bring reformation of the landscape. The disturbance caused by these topographical changes will allow the disturbance tolerant species to repopulate the habitat. This can be a transition from primary to secondary succession.
Soil : It is an abiotic factor.The growth of the plants requires suitable soil conditions. The type of soil will affect which species will inhabit the area. The soil moisture and pH greatly affect the number of plant species in an area.
Climate : It can influence the direction of succession. Climatic factors includes rain, wind etc. For example a region lacking proper rainfall the species will be tolerant to dry and drought conditions. The region with heavy rainfall, the species will be more tolerant to moisture. Wind being a climatic factor can cause wind erosion affect the soil quality. Wind can lead to heavy forest fires can therefore, wiped out community.
Answer:
Increase in transcription
Explanation:
Transcription is the process of forming RNA from DNA. It can be controlled by many factors like a repressor. Repressor can bind to the operator region of the promoter and hinder the movement of RNA Polymerase enzyme, halting the process.
Here, it is given that the repressor needs to first bind to an effector molecule X. Once it binds to X, it is activated and then it can bind to operator of gene A to inhibit its transcription. If the X binding domain on repressor is mutated it wont be able to bind to X. Thus it wont get activated and wont be able to attach to operator region to inhibit transcription. Hence, transcription process will keep going on uncontrolled.
